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Q2 Physio test 3 > Microcirculation > Flashcards

Flashcards in Microcirculation Deck (35)
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1
Q

Arterioles innervation

A

Sympathetic:
α1-adrenergic
β2-adrenergic

2
Q

α1-adrenergic receptors where?

A

skin

3
Q

Activation of α1-adrenergic receptors results in?

A

(contraction of VSM)
↓ diameter
↑ resistance
↓ flow

4
Q

β2-adrenergic receptors where?

A

skeletal mm

5
Q

Activation of β2-adrenergic receptors results in?

A

(relaxation of VSM)
↑ diameter
↓ resistance
↑ flow

6
Q

Other effectors of arteriole resistance

A

circulating catecholamines

7
Q

Vein/Venule wall layers

A

endothelial
elastic tissue
smooth mm
CT

8
Q

Sympathetic stim of Vein/Venule results in?

A

venoconstriction ->
↓ compliance for venous return ->
↓ unstressed vol

9
Q

Capillary perfusion depends on?

A

(not all perfused at same time)
metabolic needs of the particular tissue,
dilation/contr of precapillary sphincters

10
Q

Precapillary sphincter regulated by?

A

sympathetic innerv of smooth mm,

metabolites from tissues

11
Q

Solute/Gas Exchange across capillary wall via what kind of diffusion?

A

simple

solutes/gas can go through or between endothelial cells

12
Q

O2 and CO2 (lipid soluble) diffusion driven by?

A

Partial pressure gradient for the gas and

Surface area

13
Q

H2O, Glucose, AA (H2O soluble) diffuse via?

A

aqueous clefts between endo cells

14
Q

Proteins diffusion?

A

Too large to cross clefts,

Retained in vascular compartments

15
Q

Clefts in Brain vs Kidneys/Intestines

A

Brain: tight clefts, very little protein transfer

Kidney/Int: fenestrated clefts, some protein transfer

16
Q

Most important mechanism for fluid transfer across capillary wall is?

A

Bulk flow

17
Q

Bulk Flow driven by?

A

hydrostatic P
osmotic (oncotic) P
(Startling Pressures)

18
Q

Role of Lymphatics

A

return ISF and proteins to vascular compartments

19
Q

Location of Lymphatics

A

ISF near capillaries

20
Q

Structure of Lymphatics

A

one-way valves

smooth mm

21
Q

Flow of Lymphatics

A

capillaries -> lymph vessels -> thoracic duct -> large veins

22
Q

Startling Eqn

A

Jv = Kf [(Pc – Pi) – (πc - πi)]

Jv = fluid movement
Kf = hydraulic conductance
Pc = capillary hydrostat P
Pi = interstitial hydrostat P
πc = capillary oncotic P
πi = interstitial oncotic P
23
Q

Startling Eqn tells us?

A

direction of fluid movement (in or out of capillary)

Magnitude of fluid mvmt per hydraulic conductance (water permeability) of wall

24
Q

Filtration is?

A

net mvmt OUT of capillary into interstitium

25
Q

Absorption is?

A

net mvmt INTO capillary from interstitium

26
Q

Kf (hydraulic conductance) is?

A

wall water permeability

↑ in glomerular caps
↓ in cerebral caps
↑ in injury

27
Q

Edema results from?

A

↑ ISF vol

ISF vol from filtration > ability of lymph to return it to circulation

28
Q

Causes of ↑ capillary hydrostatic P

A

heart failure

venous obstruction

29
Q

Cause of ↓ capillary oncotic P

A

hypoproteinemia

30
Q

Cause of ↑ hydraulic conductance

A

burn/trauma destruction of capillary wall

31
Q

Causes of ↓ lymph drainage

A

removed/irradiated lymph nodes
filariasis (parasite of lymph nodes)
lack of muscular activity

32
Q

What is Bulk Flow?

A

Movement of water and solutes together in and out of cell

33
Q

Lymph flow driven by?

A

contraction of smooth mm in lymph vessel and skeletal mm causes flow

34
Q

Oncotic pressure is what?

A

Osmotic P of proteins in vessel’s plasma,

U pulls water into circulatory system

35
Q

Oncotic pressure is opposing for to what?

A

hydrostatic P